1) Field of the Invention
The present invention relates to a magnetic disk apparatus having servo frames that store servo information and data frames that store sector data between the servo frames, and more particularly, to a magnetic disk apparatus that can improve formatting efficiency.
2) Description of the Related Art
Conventionally, a magnetic disk apparatuses serving as an external storage for a computer has servo frames that store servo information (information for carrying out position control of a head or speed control), and data frames that store sector data between the servo frames (see, for example, Japanese Patent Application Laid-open No. 2003-331527).
The magnetic disk apparatus stores sector data in which a “preamble”, a “sync mark”, an “ECC”, and a “Gap” are added to user data “512 bytes” in the data frame for each sector. The user data is managed with a fixed data size (i.e., “512 bytes”) in the magnetic disk apparatus. However, depending on a user, the user data may be managed with different data size, such as “528 bytes”.
In a conventional technology disclosed in the Japanese Patent Application Laid-open No. 2003-331527, because the user data is managed with the fixed data size (i.e., “512 bytes”), the greater the number of sectors that are stored in the data frame, the more areas that are not related to user capacity (such as the “preamble”, the “sync mark”, the “ECC”, the “Gap”) are needed, and therefore, a formatting capacity cannot be improved.
A magnetic disk apparatus having a high storage density is continuously developed in recent years. Therefore, the number of sectors stored within the data frame is markedly increasing, and even more areas that are not related to the user capacity are needed accordingly.